This trial is a double-blind, controlled study to determine the efficacy and safety of 4 different dose regimens of oral 882C87 in the treatment of herpes zoster in immune competent elderly patients. Doses of 20, 50, 100 and 200 mg 882C87 will be given orally once daily for 14 days. An oral acyclovir treatment regimen (800 mg, five times daily, 14 days) will also be included in the study as a control.